There is growing public and scientific concern regarding the possible etiologic role of environmental and/or occupational toxins in the development of reproductive disorders. Infertility is an important reproductive disorder that affects 10-15% of U.s. couples, is frequently unexplained, and impacts on the health of both future and current generations. Limited animal data and in vitro evidence of estrogenicity support the hypothesis that polychlorinated biphenyls (PCBs), a family of chemicals that are widely occurring environmental contaminants, may affect both male and female human fertility. The main objective of this project is to study the effect of exposure to PCBs on the development of infertility. Specifically, the study will be a case-control assessment of the relationship between infertility and PCB exposures in 100 cases and 100 age, gender, and neighborhood matched controls from among men and women residing in a PCB-contaminated community. A secondary objective of the study is to evaluate the relationship between infertility and PCB exposures sustained while in utero. The potential for studying any reproductive hazards of PCBs in a U.S. population is limited by relatively low exposure levels, difficulties in identifying and tracing an occupational or residential cohort, and obstacles in tracing transgenerational toxicities due to population mobility. The current study will evaluate men and women residing in Serpukhov, Russia, an industrial community 90 kilometers southwest of Moscow. This community is uniquely suited for study as its population is stable and their PCB exposures encompass a broader range, including higher levels from both occupational and environmental exposures, then would be found among most U.S. populations. The community's air, food, and water were contaminated with PCBs from a capacitor manufacturing facility operating from the 1960's-1988. Preliminary public health surveillance data from this community suggest an association between residence near the capacitor plant and reproductive disorders such as miscarriage, stillbirth, and low birth weight. Investigation of infertility's hypothesized relationship to PCB exposures in a site uniquely suited for study promises to provide new insight into this hypothesized association.